<?php
global $a, $b;
$age = 5;
//变量作用域
function show() {
    global $age; //全局变量
    static $n = 1; //静态变量
    echo $age;
    echo $n++, '<br>';
    global $a;//全局变量
    $a = 100;
    $GLOBALS["b"] = 1000;
}

show();
show();

echo $a;
echo $b;

